This invention relates to pyrolysis of combustible solid material, and is particularly concerned with a process and system for efficiently pyrolyzing and then burning combustible solid material such as waste, e.g., industrial waste, for conversion of such solid material to heat, e.g. for driving a turbine or other heat load. The term "waste" as employed herein is intended to include, but is not limited to, industrial and household refuse, agricultural waste, feed lot and animal waste, unconventional fuels, biomass, and the like.
Industrial solid waste can be in the form of a combustible solid material of varying composition. A substantial proportion of such industrial waste can be primarily of a cellulosic nature such as scrap paper, cardboard, and the like. Other types of combustible industrial waste, such as for example rubber truck and automobile tires can contain acid components such as sulfur and chlorine.
Various processes have been developed heretofore for conversion of such combustible solid material, e.g. in the form of industrial waste, to heat for producing energy. Such processes include pyrolysis of the combustible solid material to form a fuel gas containing carbon monoxide, and the combustion of such fuel gas to produce hot combustion gases for application to a heat load such as a turbine.
However, such prior art processes and systems suffer largely from being inefficient and uneconomical.
Further, where the combustible solid material such as industrial waste, e.g. in the form of automobile tires, contains acid components such as chlorine and sulfur, the resulting raw fuel gases from pyrolysis, containing such acid components present problems in connection with the further processing of such fuel gases.
Thus, if raw fuel gases containing unsaturated hydrocarbon components are cooled down, some condensation occurs and not only does the condensate polymerize and plug up the lines, but the energy in the fuel gases can be lost. Also, the acid components will be divided between the liquid and vapor phases, requiring two separate treatment processes for removal of acid components.
On the other hand, if the fuel gas were to be treated for removal of acid components after combustion, as common in present practice, there is a much greater mass of gas to be treated following combustion, and this substantially increases the expanse of the process.
One object of the present invention is the provision of an efficient and economical method and system for producing energy from combustible solid material, particularly waste material.
Another object is to provide a process for the controlled pyrolysis of pyrolyzable feed material to produce a fuel gas, affording flexibility to handle various feed material compositions, particularly derived from industrial waste.
A still further object of the invention is the provision of an efficient process for the pyrolysis of combustible solid material, particularly waste material which can contain acid components such as sulfur and chlorine, and cleaning the resultant hot fuel gas containing such acid components prior to combustion of the fuel gas, to avoid the above noted problems of the prior art practice.